Working principle of screw pump

Screw pump, also known as "screw pump" and "Archimedes screw pump". A pump that uses the rotation of spiral blades to cause the water body to spiral upward along the axial direction. It consists of shaft, spiral blade and shell. When pumping water, place the pump tilted in the water so that the inclination angle of the main shaft of the water pump is smaller than the inclination angle of the spiral blades, and the lower end of the spiral blades is in contact with the water. When the prime mover drives the screw pump shaft to rotate through the speed changer, water enters the blades and rises along the spiral flow channel until it flows out. It has a simple structure, is easy to manufacture, has a large flow rate, small head loss, high efficiency, and is easy to repair and maintain. However, it has low lift and low speed, and a transmission device is required. It is mostly used in irrigation, drainage, and lifting of sewage and sludge. It has been used in China since the 1970s.

The screw pump device includes three parts: the prime mover, the variable speed transmission device and the screw pump, as shown in Figure 1. It is specifically composed of the spiral blade 1, the pump shaft 2, the bearing seat 3 and the casing 4. The screw pump is installed obliquely between the upper and lower pools, and the lower blade of the screw pump is immersed below the water surface. When the pump shaft rotates, the spiral blades push the water in the pool into the blade groove. Under the action of the spiral rotating blades, the water is lifted up step by step along the spiral shaft until it reaches the water outlet of the screw pump. The screw pump only changes the potential energy of the fluid, which is different from the vane water pump in converting mechanical energy into potential energy and kinetic energy of the transported liquid.